For some people, especially older people, their blood pressure drops too low when they sit or stand (a condition called orthostatic or postural hypotension). Symptoms of weakness, dizziness, lightheadedness, confusion, or blurred vision develop within a short time - from a few seconds to a few minutes after standing up (especially after lying in bed or sitting for a long time) and quickly disappear when the person lies down. However, some people may fall, faint, or, very rarely, have short-term seizures. Symptoms develop more often and are more severe after exercise, drinking alcohol and/or eating a large meal, or when there is a lack of fluids (dehydration).
Some young people develop similar symptoms when standing up, but do not experience a drop in blood pressure. Often, when standing up, their heart rate rises above normal (tachycardia develops), a disease called postural orthostatic tachycardia syndrome (POTS). The cause of dizziness in such people, given normal blood pressure, is not yet clear.
Causes of dizziness
Dizziness or lightheadedness when standing up occurs as a result of dysregulation of blood pressure. Typically, when standing up, gravity causes blood to pool in the veins of the legs and torso. This causes a decrease in blood pressure and the volume of blood flowing from the heart to the brain. Low blood flow to the brain causes dizziness and other symptoms. To compensate, the nervous system quickly increases the heart rate and constricts blood vessels, which quickly returns blood pressure to normal before symptoms begin to develop. A part of the nervous system called the autonomic nervous system is responsible for this compensation.
Problems with blood pressure regulation, which can lead to dizziness when standing up, can be caused by many medical conditions. Among them:
- Impaired function of the autonomic nervous system due to diseases or medications;
- Decreased ability of the heart to pump blood;
- Decreased blood volume (hypovolemia);
- Hormonal disorders.
Causes vary depending on whether symptoms are new to developing or have already been present for some time.
Common causes of dizziness
The most common causes of new-onset dizziness when standing up include:
- Decreased blood volume (eg, due to dehydration or blood loss)
- Medications;
- Prolonged bed rest;
- Decreased adrenal function (adrenal insufficiency).
The most common causes of dizziness when standing up that have been present for a long time (chronic) include
- Age-related changes in blood pressure regulation;
- Medications;
- Dysfunction of the autonomic nervous system.
Types of pathologies
In accordance with the mechanisms of development, the symptom is divided into several varieties. He can be:
- Vaso-vaginal. A symptom appears if vascular tone sharply decreases. In this case, a weakening of the pulse, which is weakly expressed, is diagnosed. Patients experience anemia and a constant decrease in blood pressure. People who have an asthenic physique are at risk. The pathological condition is observed during active growth of children and adolescents.
- Vagal . The heart rate decreases when the vagus nerve is stimulated. A slight decrease in blood flows to the brain. The patient experiences a weakening pulse. If a person has a dense physique, then he is at risk.
- Orthostatic . If the patient changes his body position, his vision suddenly becomes dark and he loses coordination.
- Emotional . The appearance of pathology is observed during emotional experiences and stressful conditions.
- Cardiogenic . Fainting occurs due to pathologies in the cardiovascular system. This is a dangerous pathology that requires emergency medical intervention.
- Fainting during pregnancy. Occurs with anemia in women, which is accompanied by a sharp lack of hemoglobin. If a woman has low blood pressure, then the blood cannot rise to the head, which leads to a pathological condition.
When fainting occurs, it is recommended to determine its type, which will allow the patient to prescribe rational treatment.
Evaluation of patients with dizziness
People who feel dizzy or lightheaded when standing up often recover quickly by sitting down and then slowly standing up again. However, it is usually important to determine the cause of such dizziness. The following information can help patients decide whether to see a doctor and know what to expect during a doctor's evaluation.
Warning signs in patients with dizziness
Some symptoms and signs in patients who feel dizzy or lightheaded when standing up should be cause for concern. These include:
- Blood in the stool or black, tarry stool;
- Neurological symptoms, such as difficulty walking and/or loss of coordination or balance.
When to see a doctor
If alarming signs appear, or if you fall or lose consciousness, you should immediately consult a doctor. If you develop frequent or persistent episodes of dizziness when standing up, you should consult a doctor at the first opportunity. Usually a week's delay will do no harm. If you experience occasional episodes of dizziness when standing up, you should call your doctor. The doctor will decide whether the patient needs to be seen urgently, depending on other symptoms and medical history.
What does a doctor do
First, the doctor will ask questions about the patient's symptoms and medical history. They then perform a physical examination. Based on the results of a history and medical examination, it is often possible to suggest the cause of dizziness and plan the necessary examinations in each specific case.
Doctors ask:
- How long ago did dizziness appear?
- Have you ever fallen or lost consciousness during an episode of dizziness?
- Whether the patient has had conditions known to cause dizziness (such as bed rest or fluid loss);
- Does the patient have a medical condition (such as diabetes, Parkinson's disease, or cancer) that may cause dizziness?
- Whether the patient is taking medications (eg, antihypertensives) that may cause dizziness.
The doctor will then conduct an examination. The doctor will measure blood pressure and heart rate after the patient has rested in a supine position for 5 minutes. He will then measure blood pressure and heart rate again 1 minute and 3 minutes after the patient has assumed an upright position. The doctor may perform a digital examination of the rectum to look for possible gastrointestinal bleeding. An important part of the examination is a neurological examination to check strength, sensation, reflexes, balance and gait.
The most common causes of sudden dizziness—drugs, bed rest, and decreased blood volume—are usually easy to identify. In patients with long-term symptoms, examination findings such as movement problems may indicate Parkinson's disease. Numbness, tingling, or weakness may indicate a nervous system disorder.
Carrying out tests for dizziness
If the cause is not obvious (eg bed rest), testing is usually required. Your doctor will usually order an electrocardiogram (EKG), a complete blood count, and other blood tests (such as measuring electrolytes). Other tests are ordered based on the results, especially if the patient's symptoms suggest heart or nerve problems.
If doctors suspect that a drug is causing dizziness, they may suggest that the patient stop taking it and watch to see if the dizziness goes away, thereby confirming or denying the cause.
If doctors suspect disorders of the autonomic nervous system, an examination using an orthostatic stand may be prescribed. The patient lies flat on a special mechanized table for several minutes. The table is then tilted upward at an angle of 60°-80° degrees for 15-20 minutes, while blood pressure and heart rate are continuously monitored. If blood pressure does not decrease, the person is given intravenous isoproterenol (a drug that stimulates the heart) in a dose sufficient to speed up the heart rate by 20 beats per minute, and the test is repeated. This procedure takes from 30 to 60 minutes and is absolutely safe.
Causes of pathology
A prefainting state occurs when exposed to provoking factors or against the background of diseases in the human body. The pathological process is observed with : a sudden change in body position, sunstroke, overwork, dehydration, fasting, heat stroke.
The cause of presyncope is anemia, which can have different origins. It is observed with low blood pressure, especially its rapid drop. If a person takes certain medications, especially oral contraceptives, this becomes the cause of the symptom. Presyncope occurs in women during pregnancy.
The cause of the pathology may be bronchial asthma. It occurs with diseases of the thyroid gland. With acute emotional experiences and panic attacks, the risk of developing presyncope increases . They appear in heart diseases: bradycardia, arrhythmia, coronary disease, defects.
The appearance of the symptom is observed in renal and liver failure. Presyncope is diagnosed in patients with autonomic neuropathy. It appears when the body is intoxicated, which develops against the background of an infectious process. With helminthiasis and other parasitic diseases, pathology is observed in patients. This is a common symptom of a mechanical disorder in the free filling of the brain with blood.
Presyncope occurs for various reasons, so a person is advised to be attentive to his health.
Treatment of dizziness
If possible, treat any causes, including changing the dose or stopping any medications that are causing the symptom. However, many causes cannot be cured, so steps are taken to relieve symptoms. Measures include lifestyle changes and medications.
Patients who require prolonged bed rest should sit up and exercise in bed every day if possible. Rising from a lying or sitting position should be done slowly and carefully. In general, you should drink enough fluids, limit or avoid alcohol, and exercise regularly if possible. Regular moderate-intensity exercise increases muscle tone in the walls of blood vessels, which reduces the amount of blood pooling in the legs. Symptoms may be relieved by sleeping on a bed with the head of the bed raised. In some patients, increasing salt intake may increase water retention and reduce symptoms. Doctors may recommend increasing your salt intake by adding more salt to your food or taking sodium chloride tablets. However, increasing salt intake may not be recommended for people with heart disease.
Your doctor may prescribe fludrocortisone, a drug that helps your body retain salt and water, thereby preventing your blood pressure from falling when you stand up. However, this drug may cause increased blood pressure when lying down, heart failure, and low potassium levels in the blood. Sometimes doctors prescribe fludrocortisone in combination with propranolol or another beta blocker. Midodrine is a drug that causes constriction of both arteries and veins, helping to prevent blood from pooling in the veins of the legs. Side effects include tingling or numbness and itching. This drug is not recommended for patients with coronary or peripheral artery disease.
In some cases, other medications such as nonsteroidal anti-inflammatory drugs (NSAIDs), droxidopa, pyridostigmine, and octreotide may help.
Providing first aid
A large number of people wonder what to do in case of pathology. Diagnosis is carried out only after the patient’s condition has stabilized. If the patient develops symptoms of fainting, he is advised to provide first aid until specialists arrive.
The victim must be placed on a sofa or bed in a horizontal position. It is recommended to raise your legs slightly up. In this case, it is recommended to place a pillow under the lower limbs. In the room where a person is located, it is recommended to provide a flow of fresh air. It is recommended to open windows and doors indoors.
If the victim is wearing a scarf or vest, remove them. The buttons on the shirt come undone. It is recommended to do everything necessary to free the neck and chest from clothing. Before the ambulance arrives, you need to ensure complete rest for the victim.
Giving medications to the victim before the doctor arrives is strictly prohibited . If the patient has chills, it is recommended to cover him with a warm blanket. It is strictly forbidden to get out of bed until the patient’s condition has stabilized.
The main thing that older people need to know
Dizziness or lightheadedness when standing up occurs in approximately 20% of older adults. It occurs more often in people with underlying health conditions, especially high blood pressure, and in residents of long-term care facilities. Many falls occur due to dizziness when standing up. Elderly people should avoid standing for long periods of time.
The increase in incidence in older people is associated with decreased responsiveness of the receptors that control blood pressure, combined with increased stiffness of the arterial wall, leading to difficulty moving more blood volume and increased blood pressure. Decreased receptor sensitivity leads to a delay in the normal reaction of the heart and blood vessels in response to the transition to an upright position. Paradoxically, high blood pressure, which is more common in older people, can contribute to decreased sensitivity of the receptors, increasing the likelihood of developing dizziness when standing up.
Symptoms
In a pre-fainting state, the appearance of corresponding symptoms is observed. Patients experience severe weakness and increased sweating. The pathological process is accompanied by dizziness and a feeling of heat. Patients complain of lack of air.
If a presyncope occurs against the background of vegetative-vascular dystonia, then additional symptoms may occur. Patients complain of fear and anxiety, despite the absence of a reason. Patients experience increased heart rate and dark vision. The disease leads to impaired motor function.
The occurrence of presyncope during pregnancy is accompanied by a sharp attack of nausea. Women complain of excessive weakness and dizziness. The disease is accompanied by increasing ringing in the ears. With pathology, arms and legs become numb.
If the pre-fainting state is short-lived, then this is not a pathological process . If you experience frequent loss of consciousness, it is recommended to seek help from a doctor to undergo an examination and determine the cause of the pathology. This will allow you to prescribe adequate therapy for presyncope.
Key points about feeling dizzy or faint
- Dizziness or lightheadedness when standing up is usually due to decreased fluid volume in the body or dysfunction of the autonomic nervous system.
- With age, dysfunction of the autonomic nervous system to varying degrees often develops, but doctors examine all patients to rule out disorders of the nervous system.
- For a general examination of autonomic function, an orthostatic stand is used.
- Treatment includes physical measures to reduce the amount of blood pooling in the veins, regular exercise, increased salt intake, and sometimes fludrocortisone or midodrine.
Authors of the article: Andrea D. Thompson , MD, PhD, Department of Internal Medicine, Division of Cardiovascular Medicine, University of Michigan; Michael J. Shea , MD, Michigan Medicine at the University of Michigan
